This research assessed the viability of using GSMaP satellite precipitation data instead of traditional rain gauge measurements for flood prediction modeling in the Abra River Basin, Philippines. The study developed a comprehensive hydrological simulation using HEC-HMS software to determine whether satellite-based rainfall data could reliably estimate water runoff in regions with limited ground-based monitoring infrastructure. Researchers integrated satellite precipitation measurements with detailed watershed characteristics including topography, land use, and soil properties to create predictive models for flood forecasting and water resource management. 

 This study demonstrated that GSMaP satellite precipitation data can serve as an effective substitute for traditional rainfall monitoring in hydrological modeling applications within the Abra River Basin, Philippines. Using HEC-HMS software, researchers successfully developed a watershed simulation model that achieved 94% accuracy during calibration with Typhoon Mangkhut (2018) data, though performance decreased to 61% during validation with Typhoon Marce (2008) due to systematic underestimation of extreme rainfall events. The research establishes that satellite-based precipitation products provide a practical solution for flood forecasting and water management in data-scarce tropical regions, while identifying the need for bias correction techniques to improve accuracy during severe weather conditions. This framework offers a valuable methodology for implementing hydrological modeling in areas where conventional rainfall monitoring infrastructure is inadequate or unavailable.